Ok, this is a quote by the commenter: "I am not some childish gay person who demands to have such themes in every piece of art, its just that in warhammer fiction this phenomenon really lowers the potential for depth and credibility." Now, how does not portraying a character's sexuality lower the potential for credibility? This person's statement of not being someone who demands such themes in every piece of art goes right out the window by simply asking Gav this question. I have yet to read any BL novel where a character's sexuality would bring anything to the story in any way. I have noticed they've done a fine job at making Space Marine's completely uninterested in such matters.
Honestly though, BL novels are not saturated with sex (Except that one HH novel I read, what a Jezebel) so what does it really matter what their sexual preference is? About as much as it matters that my beard is super fantastic when all you guys can see is my text.